As a conventional work-machine forward/backward travelling switching apparatus, there is known the one including a transmission having a clutch that switches forward travelling or backward travelling of a travelling body by hydraulic oil supplied from a hydraulic pressure source, a forward travelling hydraulic oil flow path that allows the hydraulic oil to pass through when the clutch is set at a forward travelling side of the travelling body, and a backward travelling hydraulic oil flow path that allows the hydraulic oil to pass through when the clutch is set at a backward travelling side of the travelling body, a flow path switching mechanism that switches the flow path for the hydraulic oil supplied from a hydraulic pressure pump to a forward travelling hydraulic oil flow path side or a backward travelling hydraulic oil flow path side, and an operation input section to which an operation of causing the travelling body to travel forward or travel backward is inputted (see PTL, for example).